 Notice. New forum software under development. It's going to miss a few functions and look a bit ugly for a while, but I'm working on it full time now as the old forum was too unstable. Couple days, all good. If you notice any issues, please contact me. |
Forum Index : Windmills : My new blades
  Page 3 of 3 |
|||||
| Author | Message | ||||
| rinaldoparaipan Newbie  Joined: 18/03/2011 Location: RomaniaPosts: 21 |
Hello. Yesterday I made some tests with my turbine. I start from 4 deg AOA uo to 20 deg. Guess what is the optimum? Watch and enjoy! http://www.youtube.com/watch?v=IO9Hm14C7jQ&context=C4e41259A DvjVQa1PpcFOe2m-EfHa-C0vw7dRh6o1ehzq9RKzhfJE= |
||||
Madness Guru  Joined: 08/10/2011 Location: AustraliaPosts: 2498 |
4 There are only 10 types of people in the world: those who understand binary, and those who don't. |
||||
| VK4AYQ Guru Joined: 02/12/2009 Location: AustraliaPosts: 2539 |
6 Foolin Around |
||||
Gizmo Admin Group  Joined: 05/06/2004 Location: AustraliaPosts: 5078 |
9.005 The best time to plant a tree was twenty years ago, the second best time is right now. JAQ |
||||
| rinaldoparaipan Newbie Joined: 18/03/2011 Location: RomaniaPosts: 21 |
Paradoxically, but the best angle is ...17 deg. We have tested the turbine on both directions, charging at 12V and 24V.We measured rpm-s and the charging current. At <10 deg AOA, the turbine has a hardly start and poor performance. You can imagine the show on the street and the behavior of the other drivers seeing what we did.(Some reactions:"Yess, you don't need fuel any more", "New hybrid car?"  )
The difference is now visible:Now I have more than 75% power at the approximative same wind speed. |
||||
| Gizmo Admin Group Joined: 05/06/2004 Location: AustraliaPosts: 5078 |
Where are you measuring the angle of attack, at the tips? Glenn The best time to plant a tree was twenty years ago, the second best time is right now. JAQ |
||||
| rinaldoparaipan Newbie Joined: 18/03/2011 Location: RomaniaPosts: 21 |
Yes, the angle is measured at the tip of the blade. 
|
||||
| Gizmo Admin Group Joined: 05/06/2004 Location: AustraliaPosts: 5078 |
That is a lot of angle. It means the turbine isn't big enough to drive the alternator at its potential output. You need a lot of angle to get the torque, and make some usable power at low RPM. You would find if you changed battery voltage you would use a different angle, its all about matching the turbine to the alternator and battery voltage. But, it is making more power that it did before. So unless you want to change turbine/alternator/battery voltage, I would say you've tests down the road have found the sweet spot for your existing combination. Thats good. Glenn The best time to plant a tree was twenty years ago, the second best time is right now. JAQ |
||||
fillm Guru Joined: 10/02/2007 Location: AustraliaPosts: 730 |
I will give you my opinion for what its worth , as I have said before , your ability to design and build this Wind Gen is one of the best I have seen here . From what you have stated earlier in the thread and I am unsure of which alt you are using , the last turn count you mentioned, your coils are wound at 88 turns of 2mm wire with 60 x 30 x 15 . Did you do any testing to get volts per turn to work out your desired cut-in rpm? It seems that you are trying to turn a high TSR blade into a low speed torque blade by increasing the AOA to 17deg , and compensate for a low cut-in . In my AX which I use 50 x 12 N38H round neos , it is basicly wound for 24V with 70 turns and would have what I would think much lesser flux denisity than yours , I have a 3.15m/Dia blade set which are the GOE222 , they are are basicly a high torque blade and they are set at recomended min AOA of 8deg (max is 10) and cut-in is at 110 RPM . I run it at 48V and use a Cap/doubler to keep the cut-in at 110rpm in 2.5m/s. I have tried loading the blades up at 60RPM with dismal results . I would suspect that you are getting better results with 24v while 12V is very poor , do you have any cut-in rpms . I feel bad saying this , but those beautiful blades at 17Deg AOA, it just is not doing them justice . PhillM ...Oz Wind Engineering..Wind Turbine Kits 500W - 5000W ~ F&P Dual Kits ~ GOE222Blades- Voltage Control Parts ------- Tower kits |
||||
| rinaldoparaipan Newbie Joined: 18/03/2011 Location: RomaniaPosts: 21 |
After a lot of tests and calculations, discussions. etc I have a real turbine. Yesterday at a 2m/s wind and 56rpm I had 6A charging(my system is on 12V). The new blades are manufactured based on Hugh Pigott details, but with a small improvement at the chord profile.The diameter is 4,2m. I'm waiting for winter winds!!! Unfortunately, the old glass fiber blades(3,5m diameter) were not able to produce what I expected and causing me a lot of disappointments. It seems the profile is not the best one.Hugh told me that the blades are slower compared with his blades and he was right. PS: Please visit my web site, I need visitors from Australia. www.ecoalternativ.ro 
|
||||
| Page 3 of 3 |
|||||
 Print this page |
